Filter for a tobacco product

ABSTRACT

The invention relates to a cigarette holder-type component, which is intended to be attached to a tobacco product and can be adapted to the suction head of the tobacco product so that the smoke travels through the component during smoking. The component contains porous material, into which an aqueous solution containing at least one aldehyde-binding compound has been absorbed to form an aldehyde-binding filter. In the component that is to be attached to the tobacco product, the water content of the material is kept at a level where the aldehyde-binding compounds are capable of reacting with the aldehydes in the smoke, changing them into a harmless form.

The invention relates to a component according to the preamble of Claim 1, which is intended to be attached to a tobacco product.

Both alcohol and smoking are risk factors for the cancers of the upper alimentary tract, and their joint use multiplies the risk of the upper alimentary tract cancer to as high as 150-fold (Salaspuro, M. Best Pract Res Clin. Gastroenterol (2003) 17:679-94 and Francheschi et al. Cancer Res (1990) 50:6502-07).

The inclusion of compounds in cigarettes or filters, which bind harmful substances from the cigarette smoke, has been suggested in several patent specifications. For example, specification U.S. Pat. No. 5,829,449 suggests adding to tobacco, cigars, pipes or filters a composition that binds harmful substances from cigarette smoke. The suggested composition contains L-glutathione, a source of selenium, such as L-selenomethionine or L-selenocysteine. The composition might also contain L-cysteine or N-acetylcysteine. This antioxidant complex was suggested to be dispersed as a powder, a stable solution or an aqueous emulsion in tobacco or the filter.

Patent specification U.S. Pat. No. 4,532,947 suggests the use of non-toxic salts of 2-mercaptoalkalene-sulphonate, and/or cysteine and acetylcysteine in cigarette filters or holders containing a filter.

Patent specification EP 1,541,043 describes a cigarette filter containing amino acids, amino acid salts, and a moisturizing agent. The moisturizing agent can comprise glycerine, sodium propionate or sodium lactate.

The cigarette filter described in patent specification U.S. Pat. No. 5,860,428 comprises a porous substrate, in which a humectant, such as sodium pyroglutamate has been dispersed. The hydrophilic humectant absorbs moisture from the cigarette smoke and releases the moisture to be wet-filtered in the porous substrate. The specification states that the filter can contain factors, which inactivate the toxic components of the smoke. Such factors include antioxidants and radical scavengers, such as glutathione, cysteine, N-acetylcysteine, mesna, etc. However, the specification does not mention the amounts, in which these substances should be used.

Patent specification PCT/FI2005/000429 suggests a separate preparation or a composition that is added to the tobacco product, filter or cigarette holder, binding the aldehydes that enter the saliva during smoking. For binding the aldehydes, compounds were used that contained a free sulphhydryl and/or amino group, such as cysteine.

Preparations that are sucked or chewed in the mouth and contain amino acids, such as L-cysteine, selenomethionine, taurine or arginine, ascorbic acid, vitamins A and E, have been suggested to be used in decreasing the effect of the harmful free radical compounds that are formed in connection with using tobacco products or being exposed to the same. It is believed that, after being absorbed, amino acids affect in various tissues (Hersch, U.S. Pat. No. 5,922,346, Hersch, International Patent Application No PCT/US98/12617).

The present invention tries to solve at least some of the problems of the known technology.

The purpose of the present invention is to provide a component, which can be attached to the tobacco product and which is capable of removing an essential part of the aldehydes in the smoke of the tobacco product.

More specifically, the composition according to the invention is characterized by what is stated in the characterizing part of claim 1.

In solutions according to the known technology, the problem with filters or other solutions that bind harmful substances from smoke has been that the filter has dried or been too dry already from the start, so that the filter has not bound the harmful compounds as desired. The present invention is based on the fact that the material inside the component that is to be attached to the tobacco product is sufficiently moist, when the smoking starts, so that the compounds in the material, which are capable of binding aldehydes, are active.

According to the invention, compounds that are capable of binding aldehydes are absorbed as an aqueous solution into or, in another way, attached to the material, which is packed in the component that is intended to be attached to the tobacco product. When the component is tightly attached to the suction head of the tobacco product, the cigarette smoke travels through the component, and the material inside the component, containing compounds capable of biding aldehydes, binds the aldehydes from the cigarette smoke so that the aldehyde content cannot rise to a harmfully high level in the mouth and the saliva. As the compounds, which are capable of binding aldehydes, bind aldehydes in the aqueous phase, the material that contains the aldehyde-binding compounds should be moist enough at the beginning of smoking for the binding reaction to take place.

The purpose of one advantageous embodiment of the present invention, in particular, is to provide a solution, due to which the capability of the component, which is to be attached to the tobacco product, to bind harmful aldehydes is preserved during the storage of the product.

According to a preferred embodiment of the invention, the compounds capable of binding aldehydes are absorbed into the porous material as an aqueous solution, and the purpose is to keep the water content of the material high enough until the filter with its material is utilized. The high enough water content herein means that the aldehyde-binding compounds in the material remain active, i.e., they are capable of binding the aldehydes into a form harmless to health.

According to a preferred embodiment of the invention, the moisture in the material contained in the component that is attached to the tobacco product is retained by means of moisture barriers. The moisture barriers are used to fully or partially protect the component that is attached to the tobacco product.

According to another preferred embodiment of the invention, the filter material containing the aldehyde-binding compounds is packed in a container, which can be inserted into the component that is attached to the tobacco product. The container can fully or partially be protected by means of the moisture barriers.

By means of the filter according to the invention, capable of binding aldehydes, at least 60%, typically at least 80%, preferably at least 85%, more preferably at least 90%, and most preferably at least 95% of the aldehydes contained in the smoke of the tobacco, cigar, pipe or other tobacco product can be bound.

The use of the aldehyde-binding filter is simple. The component containing filtering material is attached to the tobacco product in a similar manner as the mouthpieces or cigarette holders on the market. According to the preferred embodiment of the invention, the component is fully or partially protected by means of the moisture barriers. The moisture barriers are removed from the ends of the component, or the component is removed from its package that serves as the moisture barrier. The filter is immediately ready for use. In embodiments, wherein the filtering material contained in the component contains a sufficient amount of aldehyde-binding compounds, the component can be used during more than one use (time of smoking) of the tobacco product.

According to another preferred embodiment of the invention, before use, a container containing the aldehyde-binding filter material is added to the component, such as the mouthpiece or the cigarette holder. The container is preferably partly or fully protected by means of the moisture barriers. Before use, the moisture barriers are removed and the container is inserted into the component that is to be attached to the tobacco product.

DESCRIPTION OF THE FIGURES

FIG. 1 shows the filtering effect of a filter moistened with a water-cysteine solution on the content of the carcinogenic aldehyde, acetaldehyde, occurring in cigarette smoke. The use of the cysteine filter lowers the content of acetaldehyde in saliva, which is measured during smoking, considerably below the limit value that is internationally set for its carcinogenicity.

FIG. 2 A-C shows a top view of the tobacco product and the component (cigarette holder) that can be attached thereto (FIG. 2A), and a cross section from the side so that the component is separate from the tobacco product (FIG. 2B) or attached to the tobacco product (FIG. 2).

FIG. 3 shows a cross section of the component (the cigarette holder) as viewed from the end of the holder (FIG. 3A) and from its side (FIG. 3B). FIG. 3C shows the cigarette holder as viewed from the end of the holder.

FIG. 4 shows a side view of the tobacco product, the component that can be attached to the tobacco product being attached between its attachments.

FIG. 5 shows a packaging sheet, wherein the components that can be attached to the tobacco product have been packed.

In the following, the present invention is examined closely by means of a detailed description and application examples.

The “tobacco product” refers to any tobacco product, such as a cigarette, cigar or pipe. The tobacco product can already include a conventional filter or the product can be without a filter. However, it is preferable that the filter does not prevent the smoke from drifting through the component (the cigarette holder, the aldehyde-binding filter) that contains the aldehyde-binding material according to the invention.

“Smoking” herein refers to the use of the tobacco product, such as the cigarette, cigar or other tobacco product.

The “component that can be attached to the tobacco product” can also be called a cigarette holder or a filter. In that case, it refers to the filter that binds aldehydes, as distinct from the conventional filters that are used in tobacco products.

Typically, the component that is to be attached to the tobacco product has the shape of a cigarette holder or a mouthpiece.

The solutions according to the invention are now examined with reference to FIG. 2-5.

FIG. 2 shows a component 1 according to the invention that is to be attached to the tobacco product, and the tobacco product 2. In FIGS. 2A and 2B, the component 1 and the tobacco product 2 are separate, and in FIG. 2C, connected to each other. In FIG. 2A, the component 1 and the tobacco product 2 are shown from the top, in FIGS. 2B and 2C as a cross section viewed from the side. The component 1 that is intended to be attached to the tobacco product comprises a cylindrical space 13, which is open at both ends thereof and essentially hollow inside, the component being closely adaptable to the suction head 12 of the tobacco product 2. When being adapted to the tobacco product, both ends of the component 1 should be open, so that the smoke drifts through the component during smoking. The component 1 can also be called a cigarette holder or a filter. The tobacco product shown in FIG. 2 also contains a conventional filter 14.

The space 13 inside the component 1 that is intended to be attached to the tobacco product contains porous material 3, into which an aqueous solution containing at least one aldehyde-binding compound has been absorbed, or to which at least one aldehyde-binding compound has been attached in another way. The material containing aldehyde-binding compounds herein can also be called a filter material. At the end of component 1, which is adaptable to the suction head 12 of the tobacco product, there is an empty space 15 that is free of material 3. When adapting the component 1 to the tobacco product 2, the suction head 12 of the tobacco product goes inside the empty space 15 at the end of the component 1, so that the edge 16 of the adapting area covers the end 12 of the tobacco product.

After the filtering part of the component has been made, the material 3 should be moist. It is preferable to moisten the material with 20-500 μl, more preferably 20-400 μl, most preferably 50-250 μl of water, or if the aldehyde-binding compounds are included in the aqueous solution, of the aqueous solution containing the aldehyde-binding substance. The amount of aqueous solution, which is needed for moistening the material, naturally, depends on the length of the component (the cigarette holder) and the amount of material. The water content of the material 3 in the component 1 can be kept essentially unchangeable by means of moisture barrier(s) 4, 5, which can be opened or removed before starting to smoke.

According to another embodiment of the invention, the filter material is moistened before use. However, it should then be ensured, that the aldehyde-binding compounds in the filter material are capable of retaining their reactivity with aldehydes, even when drying. According to a preferred embodiment of the invention, the aldehyde-binding compounds are attached to the filter material in the aqueous solution, and the moisture of the filter material is kept essentially unchangeable until the tobacco product and the component containing the filter material, which is to be attached thereto, are utilized.

FIG. 3 shows a moisture barrier 4, 5 according to one solution according to the invention. It is manufactured from essentially airtight material, such as aluminium foil. The moisture barrier 4, 5 covers both ends of the component 1.

According to one preferred solution of the invention shown in FIG. 4, the component 1 can be provided with additions 8, 9, which contain projections 10, 11, which puncture the moisture barrier 4, 5, when the additions are in place. The additions can be placed at the suction head 12 of the tobacco product 2 so that the component 1 remains between the additions 8 and 9, which are tightly attachable to each other. When the moisture barriers 4, 5 have been pierced open by means of the projections 10, 11, the smoke is allowed to drift through the tobacco product 2 and the component 1.

FIG. 5 shows a packaging sheet 16 according to a preferred embodiment of the invention for packaging the components 1. The component 1 is packed into a recess 6 of the packaging sheet 16, which is made of a formable material, such as plastic, the recess preferably having a shape that conforms to the shape of the component 1. The recess 6 can be covered with a moisture barrier 17, whereby the component 1 is left in the airtight space in the recess 6. The component 1 can be pushed out of the recess 6 so that the moisture barrier 17 is torn or the moisture barrier 17 can be pulled from the top of the component. The same packaging sheet 16 can have several components 1 packed in respective recesses 6.

The porous material 3, which the aldehyde-binding compound is absorbed into or attached to in some other way, is packaged inside the component 1 so that as large as possible a surface becomes in contact with the smoke. FIG. 3 shows a way of packaging according to a preferred embodiment of the invention. According to the embodiment, material 7 is wound into the form of a roll and packed inside the component 1. In that case, the smoke is allowed to drift between the slightly spaced apart layers 18 of the material 7, and the aldehyde-binding compound in the material gets in contact with the aldehydes in the smoke. According to another preferred embodiment of the invention, cellulose can be packed as a wadding-type mass inside the component 1.

Typically, the component that can be attached to the tobacco product has an elongated shape of a cigarette holder/mouthpiece.

Inside the component 1, there is preferably a container 19, inside which the porous material 3 and the aldehyde-binding compounds are packed. The container preferably comprises a material similar to plastic. The container preferably has such a shape and size that it fits inside the component 1. The outer dimensions of the container can be, for example, 6-10 mm×30-40 mm, typically 8 mm×35 mm.

According to a preferred embodiment of the invention, the container 19 is packed and separately partly or fully protected by means of the moisture barriers. The container can be inserted into the component 1, such as the cigarette holder or the mouthpiece, which is to be attached to the tobacco product, before starting to smoke.

The porous material inside the component, such as the cigarette holder or the container, which can be attached to the tobacco product, can comprise cellulose, for example. Cellulose can be, for example, cellulose wadding or filter paper or another material that behaves in a corresponding manner. The amount of material per one cigarette holder or container inside the same can be 50-200 mg, preferably 70-150 mg, typically 90-120 mg. The amount of porous material depends on the size of the mouthpiece or the cigarette holder or the container inside the same and also on how large an amount of aldehyde-binding compounds is to be attached to the material.

The amount of aqueous solution per one component, such as the cigarette holder or the container inside the same, is preferably 20-500 μl, more preferably 20-400 μl, typically 50-250 μl. The amount of water should be sufficient to keep the aldehyde-binding compounds active.

The amount of water (or the solution, typically aqueous solution, containing the aldehyde-binding compound) in the porous material contained in the component, such as the cigarette holder or the container inside the same, is preferably 0.1-10 μl of water or aqueous solution/mg of porous material (20-500 μl/50-200 mg), more preferably 0.1-5.7 μl/mg (20-400 μl/70-150 mg), typically 0.4-2.7 μl/mg (50-250 μl/90-120 mg) of water or aqueous solution/mg of porous material. The water is typically distilled water.

The component, such as the cigarette holder or the container inside the same, which is intended to be attached to the tobacco product, preferably contains the aldehyde-binding compound in an amount, which is sufficient for binding the aldehydes contained in the smoke of at least one tobacco product. This amount is preferably 0.5 mg-100 mg, typically 10-50 mg. A larger amount is preferable, especially when the component, such as the cigarette holder or the container, is used more than once.

The amount of aldehyde-binding compounds in the aqueous solution containing the aldehyde-binding compound is preferably 1-5000 mg/ml of solution (0.5 mg-100 mg/20-500 μl of solution, more preferably 25-2500 mg/ml of solution (10-50 mg/20-400 μl of solution), typically 40-1000 mg/ml of solution (10-50 mg/50-250 μl of solution), generally 40-400 mg/ml (10-100 mg/250 μl of solution) of aqueous solution, most generally 40-200 mg/ml of aqueous solution (10-50 mg/250 μl of solution).

The aqueous solution containing the aldehyde-binding compound also refers to aqueous solutions, which have been buffered, their acid content having been adjusted and/or to which salts have been added. The binding of aldehydes and their filtering from the cigarette smoke can be improved, for example, by buffering or adjusting the acid content to a slightly alkaline or acidic direction by adding small amounts of salts to the aqueous solutions.

“Aldehydes” refer to C₁-C₇ aldehydes, which can be hydrocarbon chains with a linear, branched or cyclic structure. In addition to the aldehyde group, they can also contain other reactive groups as well as double or triple bonds between the atoms. Low-molecular aldehydes comprise formaldehyde (C₁), acetaldehyde (C₂), and acrolein (C₃) and crotonaldehyde (C₄), the latter two containing a double bond. Of these, especially acetaldehyde is important. Aldehydes herein refer to the aldehydes that occur in the smoke of tobacco products. Although in the following, we refer to acetaldehyde, in particular, the intention is to also refer to other aldehydes that are found in cigarette smoke.

According to the invention, the compounds that are obtained from aldehydes, acetaldehyde, in particular, by chemically binding, are harmless to the organs.

“Binding of aldehydes” refers to the chemical reaction between aldehyde and a compound that has a free sulphhydryl and/or amino group, aldehyde in the reaction forming a larger molecule together with an “aldehyde-binding substance”, and water being possibly formed in the reaction. Correspondingly, “binding of acetaldehyde” refers to the chemical reaction between acetaldehyde and a compound having a free amino group and/or sulphhydryl or sulphonic group, acetaldehyde in the reaction forming a larger molecule together with an “acetaldehyde-binding substance”, and water being possibly formed in the reaction. The “acetaldehyde-binding substance” preferably refers to a compound having one or more free amino groups and sulphhydryl groups or sulphonic groups. The “compound” can refer to one or more compounds.

For example, when reacting with cysteine, acetaldehyde binds itself to both the sulphhydryl and the amino group, forming 2-methyl-L-thiazolidine-4-carboxylic acid and water.

Acetaldehyde can bind itself to the amino group of almost any protein, whereby a Schiff base or a 2-methyl-imidazole ring is formed.

Cysteine and its derivatives are especially suitable for the purpose according to the invention. The most suitable amino acids in the use according to the invention comprise L- and D-cysteine, acetylcysteine, N-penicillamine or the derivatives of cysteine, which function in the same way as L- or D-cysteine. The compound is most suitably L-cysteine.

Suitable compounds for binding acetaldehyde in the organs also comprise the compounds according to the formula (I):

wherein R¹ is hydrogen or an acyl group containing 1-4 carbon atoms; R² is a sulphhydryl or sulphonic group; n is 1, 2, 3 or 4.

Amino acids or other compounds that suitably bind acetaldehyde and contain a free sulphhydryl (SH) and/or amino (NH₂) group include

L-cysteine, D-cysteine,

cysteine acid, cysteine-glycine, threo- or erythro-β-phenyl-DL-cysteine, β-tetramethylene-DL-cysteine, methionine, D-penicillamine and its N-terminal dipeptides, semicarbazide, reduced glutathione, β-mercaptoethyl amine

D,L-homocysteine, N-acetylcysteine, L-cysteinyl-L-valine,

β-β-tetramethylene-DL-cysteine, cysteinylglycine, mercaptoethyl glycine, thiamine hydrochloride, sodium metabisulphite, mercaptanes.

However, only those aldehyde-binding compounds, which show no health hazards in the dosages used, are suitable for the preparations according to the present invention.

Suitable compounds to be used in the invention also include the salts of the aldehyde-binding compounds.

The “content of acetaldehyde that is harmful/causes cancer” in human mouth, oesophagus, stomach and large intestine is 20-800 μmol/l of saliva or content of the intestine.

“In connection with smoking” herein refers to the period of time that begins from starting to smoke and ends, when the smoking is ended.

EXAMPLES Example 1 Moistened Cysteine Filter

The Materials Used in the Tests

Tobacco Marlboro Red, Amer Tupakka North State Plain, BAT

The entire filter of Marlboro Red was removed or, in some tests, 2-3 mm of the original filter was left in the cigarette.

The Cigarette Holder

In the tests, ready commercial cigarette holders/mouthpieces of Denicotea, www.denicotea.de were used. In the cigarette holders/mouthpieces, plastic cylinder-shaped “containers” were used, the filtering material being packed in the containers. The original content (intended for the removal of nicotine) of the containers was removed and replaced with the material that was used in the study. The outer dimensions of the container were: diameter 8 mm and length 35 mm.

The Filter Material

Cellulose wadding (c. 100 mg), filter paper (Whattman), Commercial filters: Smart (the importer: Altadia Finland Oy) and Ventti (Philip Morris Finland Oy),

Cysteine

Cysteine was dissolved in distilled water, 30-180 mg of L-Cysteine/1 ml. The manufacturer: Fluka, 30089.

Test Arrangements

The filter material that had been packed in plastic cylinders was moistened with a water-cysteine solution (50-250 μl), and the filter container thus made was placed in the Denicotea cigarette holder. After this, the testees smoked the cigarettes that had been placed in the mouthpieces. During smoking, saliva samples were collected from those participating in the tests and the acetaldehyde in the saliva was analyzed by gas chromatography, Perkin-Elmer, HS40, headspace Gas Chromatograph.

Results

Similar results were obtained with both tobacco brands.

-   -   The filter material that had been moistened with the         water-cysteine solution removed almost all acetaldehyde from the         saliva (95%), FIG. 1     -   The acetaldehyde contents measured from the saliva in connection         with the use of the cysteine filter decreased to considerably         below the international limit value 100 μM set for the         carcinogenicity of acetaldehyde.     -   The filterability was dependent on the amount of cysteine; FIG.         1 shows the effect of the moistened cysteine filter on the         acetaldehyde content of the saliva during smoking.

The results show that:

-   -   The filter material alone does not filter acetaldehyde.     -   The filter moistened with water does not filter acetaldehyde.     -   The filter and cysteine in solid form do not filter         acetaldehyde.     -   The results can be generalized to various tobacco brands, with         or without a filter.     -   The commercial filters do not bind water; therefore, they are         not suited for the filter material.     -   It is not preferable to use the cysteine filter together with         the original filter of the cigarette. In that case, the smoke         does not flow normally and easily through the two filters. A         small part of the original filter can be preserved, if the         material of the cysteine filter is porous enough. 

1. A component intended to be attached to a tobacco product, comprising: a cylindrical component (1), which is essentially hollow inside, the component being adaptable to the suction head (12) of the tobacco product (2) so that the smoke travels through the component during smoking, characterized in that the space (13) inside the component (1) contains porous material (3), into which an aqueous solution containing at least one aldehyde-binding compound has been absorbed, or to which at least one aldehyde-binding compound has been attached, in some other way, to form an aldehyde-binding filter, and that in the component (1) that is to be attached to the tobacco product, the water content of the material (3) at the beginning of smoking is high enough for the aldehyde-binding compounds to react with the aldehydes in the smoke.
 2. The component according to claim 1, characterized in that, after making the filtering filter, the water content of the material (3) can be retained essentially unchanged by means of a moisture barrier(s) (4, 5, 17), the barriers being openable or removable.
 3. The component according to claim 2, characterized in that the moisture barrier is made of an airtight material, such as aluminium foil.
 4. The component according to claim 2 or 3, characterized in that the moisture barrier (4, 5, 17) partly or fully covers the component (1).
 5. The component according to any one of the preceding claims, characterized in that the porous material is cellulose.
 6. The component according to any one of the preceding claims, characterized in that the water content of filter material contained in the component (1) is 0.1-10 μl/mg of filter material.
 7. The component according to any one of the preceding claims, characterized in that the amount of aldehyde-binding compound in the filter material contained in the component (1) is 0.5-100 mg.
 8. The component according to any one of the preceding claims, characterized in that the component (1) contains a container (19), inside of which the filtering material has been packed.
 9. The component according to claim 8, characterized in that the container (19) can be included inside the component (1).
 10. The component according to claim 8 or 9, characterized in that before use, the container (19) is partly or fully protected by means of moisture barriers, which can be opened or removed.
 11. The component according to any one of the preceding claims, characterized in that the aldehyde-binding compound comprises one or more free sulphhydryl and amino groups or sulphonic groups.
 12. The component according to any one of the preceding claims, characterized in that the aldehyde-binding compound comprises one or more compounds according to the formula (I)

wherein R¹ is hydrogen or an acyl group containing 1-4 carbon atoms, R² is a sulphhydryl or sulphonic group, and n is 1, 2, 3 or 4, or a salt of these compounds.
 13. The component according to any one of the preceding claims, characterized in that the aldehyde-binding compound is selected from a group comprising L-cysteine, D-cysteine, cysteine acid, cysteine-glycine, cystine, threo- or erythro-β-phenyl-DL-cysteine, β-tetramethylene-DL-cysteine, methionine, serine, D-penicillamine or its N-terminal dipeptide, semicarbazide, glutathione, reduced glutathione, β-mercaptoethylene amine, DL-homocysteine, DL-homocysteine acid, N-acetylcysteine, L-cysteinyl-L-valine, β-β-tetramethylene-DL-cysteine, cysteinyl glycine, mercaptoethyl glycine, cysteine hydrochloride, thiamine hydrochloride, sodium metabisulphite, arginine, glycine, lycine, ammonium chloride, 1,4-dithiothreitol, mercaptane, or a salt of any of these compounds.
 14. The component according to any one of the preceding claims to be used in reducing the amount of aldehydes contained in cigarette smoke in the mouth and the saliva. 